Chemical mechanical polishing (CMP) is generally known in the art. For example, U.S. Pat. No. 5,177,908 to Tuttle issued in 1993 describes a finishing element for semiconductor wafers, having a face shaped to provide a constant, or nearly constant, surface contact rate to a workpiece such as a semiconductor wafer in order to effect improved planarity of the workpiece. U.S. Pat. No. 5,234,867 to Schultz et al. issued in 1993 describes an apparatus for planarizing semiconductor wafers which in a preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen and a non-circular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. Fixed abrasive finishing elements are known for polishing. Illustrative examples include U.S. Pat. No. 4,966,245 to Callinan, U.S. Pat. No. 5,823,855 to Robinson, and WO 98/06541 to Rutherford.
An objective of polishing of semiconductor layers is to make the semiconductor layers as nearly perfect as possible. Current fixed abrasive finishing elements can suffer from being costly to manufacture. Also, current fixed abrasive finishing elements for semiconductor wafers have relatively homogenous surfaces which inherently limit their versatility in some demanding finishing applications. Still further, current fixed abrasive finishing elements do not have built into their construction a continuous phase of material on their surface which can help reinforce them and prolong their useful life while also improving manufacturability and versatility for finishing. Still further, lack of a continuous phase matrix on their surface reduces the flexibility to add finishing enhancers. Still further, a lack of the above characteristics in a finishing element reduces the versatility of the finishing method that can be employed for semiconductor wafer surface finishing. Still further, current fixed abrasive finishing pads are limited in the way they apply pressure to the abrasives and in turn against the semiconductor wafer surface being finished. These unwanted effects are particularly important and can be deleterious to yield and cost of manufacture when manufacturing electronic wafers that require extremely close tolerances in required planarity and feature sizes.
It is an advantage of this invention to improve the finishing method for semiconductor wafer surfaces to make them as perfect as possible. It is an advantage of this invention to make fixed abrasive finishing elements with a lower cost of manufacture and thus also reduce the cost of finishing a semiconductor wafer surface. It is an advantage of this invention develop a heterogeneous fixed abrasive finishing element surface having a continuous phase synthetic resin matrix to improve the versatility of the finishing elements and the methods of finishing semiconductor wafers which result. It is also an advantage of the invention to develop fixed abrasive finishing element which is reinforced with a continuous phase synthetic resin matrix. It is further an advantage of the invention to develop a fixed abrasive finishing element having a continuous phase synthetic resin matrix which can include finishing enhancers such as finishing aids. It is an advantage of the invention to develop a finishing element which has a unique way of applying pressure to the fixed abrasive elements and to the workpiece surface being finished. It is further an advantage of this invention to help improve yield and lower the cost of manufacture for finishing of workpieces having extremely close tolerances such as semiconductor wafers.
These and other advantages of the invention will become readily apparent to those of ordinary skill in the art after reading the following disclosure of the invention.